中国大陆甲型H 1N 1流感扩散模式及预防控制效果定量评价

目的 探讨取消边境体温筛查或其他预防控制措施,以及入境人员居家隔离环节这三种场景下中国大陆甲型H1N1流感传播模式.方法 根据已有研究资料和数据估计出各传播环节的相关参数,采用蒙特卡罗(Monte Carlo)方法模拟流感的传播过程.结果 边境体温筛查在一定程度上能够抑制疫情在国内的传播速度,使3个月后全国累计病例数降低约21.5%(1718例);疫情的蔓延速度将被延迟约4d.对甲型H1N1患者采取积极防控措施能有效控制疫情的传播和蔓延,使3个月后全国累计病例数比不采取防控措施时降低约93.4%(9万余例);疫情蔓延至全国的时间被延迟约15 d.如果入境者能够自觉采取居家隔离措施,则控制效果将更为明显,若分别有30%、60%和90%的入境者自觉采取居家隔离措施,则3个月后全国累计病例数分别可降低约15%(940例)、34%(2230例)和64%(4180例);且疫情蔓延至全国的时间分别延迟了约4、10、25 d.现有防控措施能够减轻疫情的严重程度,但难以遏制疫情的蔓延.结论 中国现有的甲型H1N1流感预防控制措施效果有效且必要.

Pattern on the spread of novel influenza A(HlNl)and quantitative assessment of containment in mainland China

Objective To study the epidemic tendency of emerging influenza A (H1N1) in mainland China, and to explore the different patterns of spread on the disease under the following contexts: (1) To stop the temperature screening program at the border areas of the country; (2)To stop measures of prevention and control on those identified cases and their close contacts; (3) To strengthen programs for the foreign immigrants on 'home quarantine'. Methods Under relevant parameters and information on the transmission link from different reference data, the patterns of influenza spread were simulated by Monte Carlo method. Results The temperature screening on border could inhibit the transmission of influenza A (H1N1) to some extent, so that after 3 months the cumulative number of cases will be reduced by 21.5% (1718 cases) and transmission speed of influenza A (H1N1) in mainland China will be delayed by about 4 days. Furthermore, taking positive measures of prevention and control could efficiently slow down the epidemic, so that after 3 months the cumulative number of cases will be reduced by 93.4%(about 90 thousand cases) and it would be delayed by about 15 days if influenza A (H1N1) spreads to the whole country. In addition, if the immigrants were able to practise quarantine measures consciously by themselves at home the effect of prevention and control against influenza A(H1N1) would be more significant. If 30%, 60% and 90% of immigrants would take quarantine measures home consciously, after 3 months the cumulative number of cases will be reduced by about 15% (about 940 cases), 34% (about 2230 cases) and 64% (about 4180 cases), respectively. Also, influenza A (H1N1) spreads to the whole country will be delayed by about 4 days, 10 days and 25 days, respectively. It is difficult to curb fully the development of the epidemic by taking existing control measures, and influenza A (H1N1) may spread to almost all provinces after about 3 months. Conclusion The effects of existing prevention and control measures were objectively assessed and the results showed the necessity and effectiveness of these measures against the transmission of influenza A (H1N1) , in the mainland of China.